Stop mechanism for knitting machines



July 16, 1940. T. J. STALSWORTH STOP MECHANISM FOR KNITTING MACHINES Filed Oct. 6 1939 Patented July 16, 1940 FFICE STOP MECHANISM FOR KNITTING MACHINES ThomasJ. Stalsworth, Knoxviile,Tenn., assignor of one -fourth to .William A: Stalsworthv and.

one-half to" Charles F. Clayton,

Tenn.

Application October 6,

8 Claims.

This invention relates to an improvement in stop'motions for knitting machines, particularly for ribknitting machines, such as are used for the knitting of underwear and hosiery, of the type a" "known-as cylinder and dial machines.

In the operation of such knitting machines, it is desirable to provide stop mechanismfor the machine that will be operative automatically when the knitting mechanism ceasesto function o in its normal andintended manner, as for instance, if a needle-should break, or if the thread breaks or gathers lint thereon that would produce an irregularity in the knitted goods. Attempts have been made heretofore to pro- "vide stop mechanisms for knitting machines, but these have generally been complex in structure, expensive, and usually unsatisfactory.

The object of this invention is to improve the construction of the stop mechanism and to enable it to function in two directions inrespons-e either to a break in the thread or to a lump thereon, for controllingthe stopping of the machine or signaling such irregularity in the operation. This attachment is small in size, simple in design and :construction and consequently inexpensive to manufacture, and is practical in its operation and use to accomplish thedesired result.

The invention preferably utilizes an enclosed casing containing a switch arm operating b-e- *tween contacts, the engagement with either of which will serve to close an. electric circuit to indicate or control the stopping of the machine. The switch arm is connected with a breaker arm that rides the stitch and controls the switch arm 'in response to a break in the thread or a lump thereon, thus providing two-way control that will accomplish the desired stopping action automatically in response to different irregularities or conditions in the knitting machine.

The invention is embodied in a preferred form thereof, which is illustrated in the accompanying drawingin which:

Fig. 1 is a partial front elevation of a portion of a knitting machine showing the invention app1ied thereto;

Fig. 2 is a perspective View of the attachment in its relation to the thread;

Fig. 3 is a vertical sectional view through the attachment; and

Fig. 4 is a horizontal sectional View therethrough on the line 44 of Fig. 3.

The invention is shown applied to a knitting machine of the cylinder and dial typein. which the frameof the machine is designatedgenerally 551vby .the .numeral l and is. provided ..with the usual.

Knoxville,

1939;- Serial-No; 298,304

bank ofcylinder needles 2 and dial needles 3, constructed andoperating in the usual way to form a stitch d; as shown in Fig. 2. The thread to the needles is passed through thead guides 5.

The attachment for controlling or indicating the stopping of the machine comprises an elongated tubular box ti, preferably constructed of Celluloid or other transparent insulating material, and'which box 6 has the side walls thereof sealed together and is closed at the bottom. by a cap "I which extends also over three sides of the box part way alongthe length thereof, having an out-turned supportingplate 8'that is secured to the frame 6 of the machine just behind the thread guide 5.

The opposite end of the box 6 is enclosed within a U-shaped cap 9 that embraces said end. The cap acarries an upstanding terminal post it, to which a conducting wire His adapted to be attached, which wire leads to an electric ,circuit that includes a sourceof electrical supply, such as a six volt battery, and also includes either mechanism for stopping the knitting machine when the circuit is closed or an. electrical indicator for producing a signal to warn the operator that the machine must be stopped. The caps l and 9 are of electrical conducting material, such as brass orother metal, and the supporting plate 8 serves to ground one side of the attachment to the frame of the machine, the electric circuit mentioned also being grounded thereto.

The sides of the U-shaped cap 9 carry contacts 52 on respective opposite sides of the attachment, which contacts !2 are in the form of screws threaded through the sides of the cap 9 and in to opposite sides of the box 6 with the. inner ends thereof in spaced relation from each other. Between the contacts I2 is a switch contact arm i3supported on a cross shaft M journaled in the lower end portion of the box 6,- whereby the contact arm It stands upright in the box with its upper end portion between the contacts i2. A spring I5 is interposed between one side of the contact arm l3'and the adjacent side of the box tending to move the contact arm is to the left in Fig. 1.

The shaft M carries a laterally and downwardly extending breaker arm Iii-which bears upon the stitch l between the respective banks of needles, as shown in Fig. 2. The breaker arm it normally, rides the stitch and when the machine is operatingin its normal and intended manner, the attachment is in such position that the breaker arm It will hold the switchcontact arm l3 in. an...intermediate. position. midway. between. the

The breaker arm is preferably formed of wire and may be bent slightly during installation to dispose its point in its proper position for this purpose according to the construction and characteristics of the knitting machine to which it is applied. This breaker arm is preferably formed integralwith the shaft i4 and has the contact arm I 3 securely mounted thereon rigid therewith. As shown in Fig. 3, the arm I3 is electrically connected with the cap 1 through a connection I! through which the switch arm I3 is grounded to the frame.

With the breaker arm l6 bearing at its end on the stretch between the dial and cylinder needles, 7

if a needle should break the breaker arm will rise or lower according to the needle which breaks, whereby the switch arm is will be moved into engagement with one or the other of the contacts 12, closing the circuit through the wire II to automatically stop the machine or to indicate the need for the stopping thereof by the operator. If the thread breaks during the operation of the knitting machine and clears a space between the dial and cylinder needles, this will cause the breaker arm 16 to drop down when it reaches this space, swinging the switch arm l3 into engagement with one of the contacts l2 to close the circuit. If lint or a lump of cotton should be gathered on the needles sufficiently to cause bad knitting, it will raise the breaker arm and swing the switch arm in the opposite direction also stopping the machine. Likewise, it functions to stop the machine when there is no thread in the needles and when the cloth is off the needles.

The attachment prevents breakage of the needles and waste by automatically stopping the machine when an irregularity is encountered during the knitting operation, and yet by means of a -;simple and inexpensive attachment that may be applied readily to a knitting machine.

I claim: 1. In a knitting machine having stitch forming means, the combination of stop mechanism for the machine comprising a support having spaced contacts, a switch arm arranged between the contacts and a breaker arm connected with the switch arm and extending in position to bear upon the stitch.

2. In a knitting machine having stitch forming means, the combination of stop mechanism. for the machine comprising a support having a pair of spaced contacts, a switch arm arranged between the contacts and pivotally mounted for swinging movement toward and from the contacts, and a breaker arm fixed to the switch arm and movabletherewith, said breaker arm extending in position to bear upon the stitch.

3. In a knitting machine having stitch forming means, the combination of stop mechanism for the machine comprising a support having a pair of spaced contacts connected togther and adapted to be connected with one side of an electric stop circuit, a switch arm pivotally mounted on the support and extending between the contacts for swinging movement toward and from the contacts into engagement therewith, said switch arm being adapted to be connected with the opposite side of the electric stop circuit, and

a breaker arm fixed to the switch arm and movable relative thereto, said breaker arm extending in position to bear upon the stitch and to actuate the switch arm in response to irregularities in the stitch.

4. Ina knitting machine having stitch forming contacts l2 and out of engagement therewith.

means, the combination of stop mechanism for the machine comprising a support having a pair of spaced contacts electrically connected together and having means for connection with one side of an electric stop circuit, a switch arm pivotally mounted on the support and extending between the pair of contacts and having means for connection with the opposite side of said electric stop circuit, and a breaker arm fixed to the switch arm and movable therewith, said breaker arm extend- .ing laterally from the support and having a free end in position to bear upon the stitch and to actuate the switch arm in response to imperfec tions in the stitch.

5. In a knitting machine having stitch forming means, the combination of stop mechanism for the machine comprising a support of insulating material having a pair of spaced contacts electrically connected together and having means for connection with one side of an electric stop circuit, a switch arm journaled on the support and extending between the contacts for swinging movement toward and from the same into engagement therewith, resilient means bearing against one side of the switch arm, means for connecting the switch arm with the opposite side of the electric stop circuit, and a breaker arm fixed to the switch arm and extending laterally therefrom in position to bear upon the stitch and hold the switch arm in an intermediate position between the contacts against the tension of the resilient means.

6. In a knitting machine having stitch forming means, the combination of stop mechanism for the machine comprising an elongated tubular support of insulating material having spaced contacts extending in opposite sides thereof, a cap connecting the contacts together and having a binding post thereon for connection with one side of an electric stop circuit, a switch arm journaled in the tubular support and extending between the contacts in position to engage the same, resilient means acting on the switch arm in one direction, means for connecting the switch arm with the opposite side of the electric stop circuit, and a breaker arm secured to the switch arm for moving the same against the tension of the resilient means, said breaker arm extending laterally from the support in position to bear upon the stitch and to move the switch arm in response to irregularities therein.

7. In a knitting machine having stitch forming means, the combination of stop mechanism for the machine comprising an elongated tubular support of insulating material having spaced contacts extending in opposite sides thereof, a cap connecting the contacts together and having a binding post thereon for connection with one side of an electric stop circuit, a switch arm journaled in the tubular support and extending between the contacts in position for swinging movement into engagement therewith, a spring bearing against one side of the switch arm tending to move the same in one direction, a cap secured to the under portion of the support and having a laterally extending supporting plate connected with the switch arm and adapted to be connected with the other side of the electric stop circuit, and a breaker arm secured to the switch arm and extending laterally from the support in position to bear upon the stitch for movement of the switch arm in response to irregularities therein.

8. In a knitting machine having stitch forming means, the combination of stop mechanism for the machine comprising an elongated, box of inw stop circuit, a switch arm journaled in the box and extending between the pair of contacts in position for movement into engagement therewith, said switch arm being connected with the last-mentioned cap, and a breaker arm secured to the switch arm and extending laterally and downwardly therefrom-in position to ride upon the stitch and to move the switch arm in response to irregularities therein.

THOMAS J. STALSWORTH. 10 

